I hate carbs, I really do. 400 advice

[Uncle Bob]

Ok first I need to get this off my chest, I hate taking them off and I hate trying to get them back on and then I hate having it not run right and having to repeat. The 400 was close to being parts on Ebay Saturday! I feel better now...

Anyway, the 400 starts but what is the general consensus of the issue where shutting the throttle off or blatting the throttle results in highish revs (4-5k) which die down to tick over slowly. All new seals and O-rings, though same jets (ultra sonically cleaned) and needles. Diaphragms looked fine. What I read points to air leak but can't initially see anything.

I'm resigned to the fact they will have to come off again...

Also on getting them back in again, does anyone use / recommend grease or silicon on the rubber bits to help them slide on / in easier? Just wondered.

Rob

[fossie]

Air leak sounds very plausible however ......the o rings in the carb inlet rubbers need to be factored in.
400 carbs are so small jetted that unless you've ultrasonic ally cleaned them. WITHOUT poking the brass jets with a piece of wire .... This is your life!

Get them off get 'em done , do it once. Or give up........ Been there mate but mine were just so worn out I had to renew the whole carbs.

[callyboy]

I feel your pain. I always found a drop of washing up liquid helped. Made my hands smell better anyway. Thought of changing to pods and rejetting etc ?

Pete

[johnr]

washing up liqid long term damages rubber components, it drys them out as its a degreaser. i hated the 400 carbs, theyre a fucking nightmare. i bought my 400 for 1100 quid, and spent 3 months getting it right and fettling the carbs, eventually i ended up selling it for 700 quid after i had done the carbs and it was running ok, i was just so sick of it, i was prepared to take the loss just to get it out of my sight. i wont ever buy another, theyre vile things. i stripped and ultrasonically cleaned them a couple of times, and replaced all the o rings. did you remove the plastic guides that the slides run in from inside the carb body? theres an o ring in them as well. mine were full of bits of white bath sealant. shame, cos the 400 ran well when it was running, and handled lovely, but i never had any confidence in it after that. its also worth getting some fuel stabiliser and adding it to the tank when you arent going to ride for a week or two. as well as making sure the tank isnt rusaty inside.

[Uncle Bob]

I feel your pain. I always found a drop of washing up liquid helped. Made my hands smell better anyway. Thought of changing to pods and rejetting etc ?

Pete

The pod idea did cross my mind but considering JohnR's post below in getting it to run right with standard bits not sure that might be easy! I'll see how I feel in a few weeks of fighting it...!

[Uncle Bob]

i hated the 400 carbs, theyre a fucking nightmare.

I had to laugh at your commens John else I think I would cry in despair

If only that paragraph of text was at the top of the "Sword of Water" section with **WARNING** as the subject!

Well I'm going to do another clean cycle. I did do the O-Ring in the plastic guide as well. I did bend a couple of the clips trying to get them back in when I lost, erm, a bit of patience so I will be optimisic and go with air leak for now.

Have to say though, like you said, it seemed to handle well and was smooth.

I have used Briggs and Stratton fuel stabiler as well.

[pookie]

Hi, don't know if you've seen this webpage but its very helpful, and as they say at alcoholics anonymous 'you're not alone' http://tonysleep.co.uk/info/great-gsxr4 ... ettor-saga" onclick="window.open(this.href);return false;

[callyboy]

Been on that page a few times

Peter

[johnr]

also check your coils. the ht leads screw into the coils. i discovered mine were loose. i took them out and snipped half an inch off the end and then refitted them. made a noticable difference to the stability of the slow speed running.

[Uncle Bob]

I have read the Tony Sleep page (several times). When it all went back together it wouldn't start. I did unplug the coil leads and put back on and same with CDI and then it started straight away (which made me jump as one of the plugs was still out!), so assumed a bad connection, but might double check.

Cheers